6721779 has 4 divisors (see below), whose sum is σ = 8962376. Its totient is φ = 4481184.

The previous prime is 6721769. The next prime is 6721787. The reversal of 6721779 is 9771276.

6721779 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 6721779 - 2⁵ = 6721747 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6721739) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1120294 + ... + 1120299.

It is an arithmetic number, because the mean of its divisors is an integer number (2240594).

Almost surely, 2^6721779 is an apocalyptic number.

6721779 is a deficient number, since it is larger than the sum of its proper divisors (2240597).

6721779 is a wasteful number, since it uses less digits than its factorization.

6721779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2240596.

The product of its digits is 37044, while the sum is 39.

The square root of 6721779 is about 2592.6393887311. The cubic root of 6721779 is about 188.7244100799.

The spelling of 6721779 in words is "six million, seven hundred twenty-one thousand, seven hundred seventy-nine".